1 files changed, 4 insertions, 1 deletions
diff --git a/block.c b/block.c
index 30afdcbba6..1ed9214f66 100644
--- a/block.c
+++ b/block.c
@@ -7357,7 +7357,10 @@ void bdrv_img_create(const char *filename, const char *fmt,
         goto out;
     }
 
-    if (size == -1) {
+    /* Parameter 'size' is not needed for detached LUKS header */
+    if (size == -1 &&
+        !(!strcmp(fmt, "luks") &&
+          qemu_opt_get_bool(opts, "detached-header", false))) {
         error_setg(errp, "Image creation needs a size parameter");
         goto out;
     }